As blasphemous as it may sound for a team that hasn’t been close to .500 in five years, over-confidence could be one of the 49ers’ biggest adversaries heading into Sunday’s game against the Steelers.

The 0-2 Steelers make their first visit to Levi’s with six-time Pro Bowl quarterback Ben Roethlisberger gone or the season, with top play-maker Juju Smith-Schuster yet to score a touchdown, and with a defensive unit that sometimes looks like the antithesis of the “Steel Curtain” from yesteryear.

Not surprisingly, the oddsmakers like the 49ers’ chances to go 3-0 for the first time in 21 years.

Elbow pain drove Roethlisberger out of Sunday’s 28-26 loss to the Seahawks in the second quarter, and it was announced Monday the 37-year-old will undergo season-ending surgery. So, for the first time since 2004, the Steelers will have a new starting quarterback — second-year man Mason Rudolph of Oklahoma State replaces the man who won two Super Bowls for Pittsburgh. Worse yet for Pittsburgh, it will spend more than one quarter of its salary cap this season on two players who won’t suit up — Roethlisberger ($26.2 million cap hit) and ex-Raider, current Patriot Antonio Brown ($21.2 million hit).

Sputtering stars

Running back James Conner was going to duplicate Le’Veon Bell’s production and receiver Juju Smith-Schuster was going to make everyone forget about Brown. Two games in, the Steelers and their fans are still waiting for deliveries on those promises. Conner, who’s been hobbled with a nagging knee injury, has averaged just 2.6 yards per carry and has rushed for just 54 yards. Smith-Schuster, while thankfully not duplicating any of Brown’s quibbles or quirks, so far has pedestrian averages of 5.5 catches and 81 yards in two games after making the Pro Bowl following a 111-catch, 1,426-yard season last year. Not having the threat of Roethlisberger extending plays like only he can, the 49ers should have an easier time trying to contain both Conner and Smith-Schuster again.

Coverage concerns

Steelers’ linebacker Devin Bush, the 10th pick of the draft out of Michigan, may be one of the favorites to win Rookie Defensive Player of the Year, but he’s also having some troubles covering receivers. He’s not the only Pittsburgh linebacker with pass troubles as Mark Barron has also been targeted. In fact, Seattle had 13 catches by backs or tight ends during its win over Pittsburgh.

THREE REASONS FOR 49ERS’ PESSIMISM:

Stealing a star?

The Steelers pulled off a stunning trade late Monday to acquire star safety Minkah Fitzpatrick from the Dolphins for a first-round pick. On the surface, it seems a curious move to unload what appears to be a top 10 pick next season for a defensive back not named Jalen Ramsey, but Fitzpatrick will stabilize Pittsburgh’s secondary. The Steelers allowed 61 points through two games and permitted Tom Brady and Russell Wilson to post an aggregate QB rating of 131.3, so they obviously felt something bold needed to be done. This just made things a bit tougher for Jimmy Garoppolo.

Say it ain’t so, Joe

Without Joe Staley protecting his blind side, Garoppolo’s time in the pocket could be compromised, especially considering the Steelers have a pair of stout defensive linemen in All-Pro Cam Heyward and also Stephon Tuitt, who earned a five-year, $61 million contract. 49ers rookie tackle Justin Skule will be counted on to help keep Garoppolo off the Levi’s turf, which may be a bit challenging.

One would assume at some point the Steelers would snap out of their current mess, even if only on a temporary basis. After all, Mike Tomlin knows a thing or two about winning games as he’s gone 125-68-1 with a Super Bowl title in 13 yards as the Steelers head coach. Despite the 0-2 start, there remains a lot of talent on the team and let’s not forget Pittsburgh has yet to have a losing season under Tomlin.

PROBABLE DIFFERENCE-MAKER: Mason Rudolph.

The 6-foot-5, 235-pound Rudolph certainly has Roethlisberger-like size, but now the former Oklahoma State star will need to produce at least close to what Big Ben delivered if the Steeers are going to threaten teams this year. Rudolph may not have a great arm, but scouts rave about his pocket presence. He replaced Roethlisberger against the Seahawks last week and completed 12 of 19 passes for 112 yards and a pair of TD tosses to ex-49ers tight end Vance McDonald. With Big Ben, the Steelers led the NFL in passing attempts with 675, so it’s likely Rudolph will come out throwing Sunday.